The security hole, tracked as CVE-2022-27924 and described as a Memcache injection issue, allows an unauthenticated attacker to steal cleartext credentials from a targeted Zimbra instance without any user interaction.

An attacker can leverage the compromised credentials to access the victim’s emails, from where they could escalate their access within the targeted organization and obtain sensitive information. Access to mailboxes can also allow the attacker to impersonate users and spy on victims.